In recent years, it is required that display driving circuits for driving liquid crystal panels be reduced in scale in order to achieve slim bezel of liquid crystal display devices. Because scales of the display driving circuits largely affect the number of elements of transistors for configuring circuits, it is important to reduce the number of transistors.
The following description will discuss, as an example, a shift register (see, for example, Patent Literature 1) for use in a conventional display driving circuit. FIG. 77 is a block diagram illustrating a schematic configuration of each stage (hereinafter referred to as “unit circuit”) of a shift register for use in a scanning signal line driving circuit. The unit circuit 110 includes a set-reset flip-flop circuit 110a and a switch circuit 110b. The flip-flop circuit 110a has (i) a set terminal (S terminal) which is supplied with an output SROUT(k−1) of a preceding unit circuit 110 as a set signal (S signal), (ii) a reset terminal (R terminal) which is supplied with an output SROUT(k+1) of a subsequent unit circuit 110 as a reset signal (R signal), (iii) an initialization terminal (INIT terminal) which is supplied with an initialization signal (INIT signal), (iv) an output terminal (Q terminal) from which a Q signal is outputted, and (v) an inverted output terminal (QB terminal) from which a QB signal is outputted. The switch circuit 110b includes an analog switch ASW. The analog switch ASW has (i) a gate terminal on an N channel side which gate terminal is connected to the Q terminal, (ii) a gate terminal on a P channel side which gate terminal is connected to the QB terminal, (iii) a source terminal which is connected to a clock terminal, and (iv) a drain terminal which is connected to an output terminal OUT.
The shift register, which includes the above unit circuit 110 at each stage, carries out a shift operation to sequentially supply output signals SROUT1 to SRMOUTn to gate lines GL1 to GLn, respectively.